Oil and gas production handbook An introduction to oil and gas production

 
Figure 40. Greenhouse emissions 
Source: Wikipedia Commons
 

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138 
 
There are many mechanisms affecting the overall balance of greenhouse 
gases in the atmosphere. CO
2
 has been measured both directly and in ice 
cores, and has increased from a pre-industrial value of around 250 ppm to 
385 ppm today. Methane has increased from 1732 to 1774 ppb (parts per 
billion). 
 
There is no full model that describes the net effect of these changes. It is 
well accepted that without CO2, methane and water vapor, the global 
average temperature would be about 30 ºC colder. The current data 
correlates well with a current global average temperature increase from a 
pre-industrial global average of 13.7 ºC to 14.4 ºC today. The atmosphere 
and seas have large heat trapping capacity, which makes their temperatures 
rise. These temperature rises lag behind greenhouse gas temperature 
increases. It is therefore predicted that the temperature will continue to rise 
by about 1ºC even if there were no further increase in levels of CO
2
 and 
methane. 
  
The heat capacity of the atmosphere and seas also means that when the 
temperature increases, there will be more energy stored in the atmosphere, 
which is expected to drive more violent weather systems.